1. Field of the Invention
The present invention relates to graphitized carbon. In particular, the invention relates to processes for making high surface area graphitized carbon, which preferably is suitable for catalyst applications.
2. Discussion of Background Information
Fuel cells are electrochemical devices in which the energy from a chemical reaction is directly converted to current electricity. During operation of a fuel cell, a continuous flow of fuel, e.g., hydrogen (or a liquid fuel such as methanol), is fed to the anode while, simultaneously, a continuous flow of an oxidant, e.g., air, is fed to the cathode. The fuel is oxidized at the anode causing a release of electrons through the agency of a catalyst. These electrons are then conducted through an external load to the cathode, where the oxidant is reduced and the electrons are consumed, again through the agency of a catalyst. The constant flow of electrons from the anode to the cathode constitutes an electrical current which can be made to do useful work.
Traditionally, fuel cell catalysts comprise an active phase disposed on electrically conductive support particles such as carbon blacks. In addition to the composition and structure of the active phase employed, the composition and structure of the support particles is of utmost importance. In general, support particles should have a high surface area so as to maximize the surface on which active phase may be disposed and thereby maximizing reactant/catalyst contact.
In addition, support particles should be sufficiently durable under fuel cell operating conditions. For most fuel cell applications, the support phase should be sufficiently durable under load cycling conditions and at high potentials. Durability of commonly used carbon supports is a major challenge due to corrosion at high cell potentials and temperatures, and especially during start/stop cycles typical for transportation applications. Thus, the need exists for highly durable high surface area support particles suitable for use as catalyst supports in fuel cell applications, and in particular automotive fuel cell applications.